Rr. Spinales The branches of the ramus dorsalis of an arteria intercostalis posterior that enter an intervertebral foramen include one that tracks behind the corpus vertebrae (ramus postcentralis), one that tracks in front of the lamina arcus vertebrae (ramus prelaminaris), one to the anterior root of the spinal nerve (arteria radicularis anterior), one to the posterior root of the spinal nerve (arteria radicularis posterior), and one that anastomoses with the anterior spinal artery (arteria medullaris segmentalis).